Effects of Raw Material Content on Efficiency of TiN Synthesized by Reactive Ball Milling Ti and Urea

Ti and urea mixed according to the molar ratios of 2：1, 3：1 and 4：1 axe milled under the same condition. The structures of the as-synthesized powders are analyzed by an x-ray diffractometer （XRD）. The decomposed temperature of the urea and the products decomposed are characterized by differential scanning calorimetry （DSC） and thermogravimetry analysis-Fourier transform infrared （TG-FTIR） spectrometry. The results show that the reaction progress is a diffusion reaction. The efficiency of TiN synthesized by reactive ball milling can be increased by increasing the content of Ti. The reactive ball milling time decreases from more than 90 h to 40 h correspond- ing to the content ratio between Ti and urea increasing from 2：1 to 4：1. Ammonia gas （NH3） and cyanic acid （HNCO）, the decomposed products of urea, react with the refined Ti to form TiN. The grain refinement of Ti has a significant effect on the efficiency of reactive ball milling.